This invention relates to a protective boot for use with a pole-mounted circuit interrupter of the type commonly used in connection with high voltage power lines.
The high voltage circuit interrupter is well-known in the prior art and generally consists of a number of standard switches mounted on a crossbeam. The switches are generally used to break the individual power lines when it is necessary to effect repairs or reroute the currrent. However, because of the nature of these switches, the electrically conductive portion is uninsulated. At the same time, as a safety measure, the crossbeam on which the switches are mounted as well as other portions of the switching mechanism itself are grounded. Under these circumstances, it is of paramount importance that the portion of the switch along with the wires carrying the high current be constantly separated from the grounded section of the interrupter switch, or a short circuit would result causing great damage to the circuit interrupter and disrupting the current flow in the power lines.
To prevent this, a number of standard high voltage ceramic insulators are used to separate the current carrying parts of the switches from the grounded pieces, and therefore, under normal conditions, short circuits would not occur. Under actual operating conditions, however, it has been found that squirrels or other types of climbing animals have accidentally bridged the gap between the conductive, current carrying parts of the switches and the grounded portions thereby causing a short which effectively destroys one or more of the switches and requires the complete replacement of the entire circuit interrupter.
A number of techniques have been tried in the prior art to prevent accidental short circuits of this nature, but none has been entirely successful. In some cases, the circuit interrupters have been hung upside down or fiberglass crossbeams used, but both have proved to be impractical in view of the amount of work and expense involved in altering the large number of already installed interrupters. And further, neither method has been entirely effective as exposed grounded parts remain accessible. Another attempted solution has been the use of a dielectric paint to cover and thereby insulate the metal parts of the grounded portion of the interrupter. This has been ineffective as the paint can be easily burned through when contacted by the very high current involved thereby creating a short. Further, the paint is very susceptible to damage by the elements and often chips making the insulating protection incomplete.
Consequently, because of the wide use in the power industry of the circuit interrupters, there is a serious need for an effective means for protecting the devices from this destructive shorting out which can be easily applied to existing circuit interrupters which are already in use and mounted on the poles.